2006 volvo 780 problems with shifting and acceleration--what causes this?

[jcrew]

Hi need help on getting volvo repaired have taken to shop and their not sure--problem seems to be getting worse. Please let me know if you've had similar problem and how you fixed it. This is an automatic and I already replaced one of the harnesses.

[kazungu80]

my friend had simillar problem.But his was in freightliner century with a detroit 60 series.we tried a couple of things and it finnaly worked.we first tried the cheapest way by changing the speed sensor which happened not to be the one.if the ecm doesnt get the correct info of the speed the transmission is moving at it wont let it shift or accerelate.second thing that fixed it was that he bought a used ecm and took it to the dealar to get programmed to the parameters of the old one(ECM).after doing all this it solved the problem and the truck was running like a champ again.the second solution costed him like 2000 dollars.cost of the used ECM and the programming cost at the dealer.good luck and let me know how it goes

[bigkev1115]

What exactly kinds of problems that you re having with the automatic? I can try to help

[Pablo-UA]

what tranny?